Intravascular heat exchange catheter with rib cage-like coolant path

ABSTRACT

An intravascular heat exchange catheter has serpentine-like supply and return conduits circulating working fluid with a heat exchange system to warm or cool a patient in which the catheter is intubated.

I. FIELD OF THE INVENTION

The present application relates generally to patient temperature control systems.

II. BACKGROUND OF THE INVENTION

It has been discovered that the medical outcome for a patient suffering from severe brain trauma or from ischemia caused by stroke or heart attack or cardiac arrest is improved if the patient is cooled below normal body temperature (37° C.). Furthermore, it is also accepted that for such patients, it is important to prevent hyperthermia (fever) even if it is decided not to induce hypothermia. Moreover, in certain applications such as post-CABG surgery, skin graft surgery, and the like, it might be desirable to rewarm a hypothermic patient.

As recognized by the present application, the above-mentioned advantages in regulating temperature can be realized by cooling or heating the patient's entire body using a closed loop heat exchange catheter placed in the patient's venous system and circulating a working fluid such as saline through the catheter, heating or cooling the working fluid as appropriate in an external heat exchanger that is connected to the catheter. The following U.S. patents, all of which are incorporated herein by reference, disclose various intravascular catheters/systems/methods for such purposes: U.S. Pat. Nos. 6,881,551 and 6,585,692 (tri-lobe catheter), U.S. Pat. Nos. 6,551,349 and 6,554,797 (metal catheter with bellows), U.S. Pat. Nos. 6,749,625 and 6,796,995 (catheters with non-straight, non-helical heat exchange elements), U.S. Pat. Nos. 6,126,684, 6,299,599, 6,368,304, and 6,338,727 (catheters with multiple heat exchange balloons), U.S. Pat. Nos. 6,146,411, 6,019,783, 6,581,403, 7,287,398, and 5,837,003 (heat exchange systems for catheter), U.S. Pat. No. 7,857,781 (various heat exchange catheters).

SUMMARY OF THE INVENTION

A catheter includes a heat exchange supply conduit configured to supply working fluid received from a source of working fluid to a distal location, and a heat exchange return conduit communicating with the supply conduit at the distal location and configured to return working fluid to the source. At least a portion of the supply conduit and/or at least a portion of the return conduit is configured in a serpentine configuration when working fluid flows therethrough.

In example embodiments, at least a portion of the supply conduit and at least a portion of the return conduit are configured in a serpentine configuration when working fluid flow therethrough. Furthermore, serpentine portions of the supply conduit establish axially longer segments and axially shorter segments and serpentine portions of the return conduit establish axially longer segments and axially shorter segments. At least one axially shorter segment of the return conduit is bordered by and axially between transverse legs of axially longer segment of the supply conduit and at least one axially shorter segment of the supply conduit is bordered by and axially between transverse legs of an axially longer segment of the return conduit.

As discussed in one example below, when the conduits are inflated with working fluid, a proximal-most transverse segment of the supply conduit ends at a first distally-extending axially-oriented segment, which merges at a distal end with a second transverse segment, which in turn merges at an opposite end of the second transverse segment with another distally-extending axially-oriented segment. Likewise, when the conduits are inflated with working fluid, a distal-most transverse segment of the return conduit ends at a first proximally-extending axially-oriented segment, which merges at a proximal end with a second transverse segment, which in turn merges at an opposite end of the second transverse segment with another proximally-extending axially-oriented segment.

In non-limiting examples, in each conduit, lengths of the axially-oriented segments sequentially alternate between a short length and a long length, while in contrast each transverse segment has substantially the same length as the other transverse segments. Additionally, a long axially-oriented segment of the supply conduit axially spans a short axially-oriented segment of the return conduit, and likewise a long axially-oriented segment of the return conduit axially spans a short axially-oriented segment of the supply conduit. Short axially-oriented segments of the conduits may be substantially straight and parallel to a long axis of the catheter, while long axially-oriented segments the conduits can be concave.

In another aspect, a catheter includes a heat exchange supply conduit configured to supply working fluid received from a source of working fluid to a distal location. A heat exchange return conduit communicates with the supply conduit at the distal location and is configured to return working fluid to the source. At least a portion of the supply conduit and at least a portion of the return conduit are configured in a serpentine configuration when working fluid flow therethrough. Serpentine portions of the supply conduit establish axially longer segments and axially shorter segments and serpentine portions of the return conduit establish axially longer segments and axially shorter segments. At least one axially shorter segment of the return conduit is bordered by and spaced axially between transverse legs of an axially longer segment of the supply conduit and at least one axially shorter segment of the supply conduit is bordered by and axially between transverse legs of an axially longer segment of the return conduit.

In another aspect, an intravascular heat exchange catheter has serpentine-like supply and return conduits circulating working fluid with a heat exchange system to warm or cool a patient in which the catheter is intubated.

The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an example catheter engaged with an example heat exchange system;

FIG. 2 is a perspective view of the heat exchange region showing only the coolant supply and return lumens and omitting infusion lumens for clarity; and

FIG. 3 is a close up view of the heat exchange region.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially to FIG. 1, an intravascular temperature management catheter 10 is in fluid communication with a catheter temperature control system 12 that includes a processor executing logic that in some non-limiting examples is in accordance with disclosure in the above-referenced system patents to control the temperature of working fluid circulating through the catheter 10 in accordance with a treatment paradigm responsive to patient core temperature feedback signals. In accordance with present principles, the catheter 10 can be used to induce therapeutic hypothermia in a patient 14 using the catheter, in which coolant such as but not limited to saline circulates in a closed loop, such that no coolant enters the body. Such treatment may be indicated for stroke, cardiac arrest (post-resuscitation), acute myocardial infarction, spinal injury, and traumatic brain injury. The catheter 10 can also be used to warm a patient, e.g., after bypass surgery or burn treatment, and to combat hyperthermia in, e.g., patient suffering from sub-arachnoid hemorrhage or intracerebral hemorrhage.

As shown, working fluid such a refrigerant may be circulated between the heat exchange system 12 and catheter 10 through supply and return lines 16, 18 that connect to the proximal end of the catheter 10 as shown. Note that as used herein, “proximal” and “distal” in reference to the catheter are relative to the system 12. A patient temperature signal from a catheter-borne temperature sensor may be provided to the system 12 through an electrical line 20 or wirelessly if desired. Alternatively, a patient temperature signal may be provided to the system 12 from a separate esophageal probe or rectal probe or tympanic sensor or bladder probe or other temperature probe that measures the temperature of the patient 14.

The catheter 10, in addition to interior supply and return lumens through which the working fluid is circulated, may also have one or more infusion lumens connectable to an IV component 22 such as a syringe or IV bag for infusing medicaments into the patient, or an instrument such as an oxygen or pressure monitor for monitoring patient parameters, etc.

The catheter 10 can be positioned typically in the vasculature of the patient 14 and more preferably in the venous system of the patient 14 such as in the inferior vena cava through a groin insertion point or the superior vena cava through a neck (jugular or subclavian) insertion point.

Now referring to FIGS. 2 and 3, the catheter 10 includes a distal portion 100 which has a supply port 102 configured to communicate with the supply line 16 in FIG. 1 and a return port 104 configured to communicate with the return line 18 in FIG. 1. A heat exchange supply conduit 106 receives working fluid from the supply line 16 and, hence, from a source of working fluid such as the heat exchange system 12. The supply conduit 106 conveys the working fluid to a distal location 108, where it joins a heat exchange return conduit 110 to return working fluid through the return port 104 and thence to the source.

As shown, at least a portion of the supply conduit 106 and/or at least a portion of the return conduit 110 is configured in a serpentine configuration when working fluid flows therethrough. In the example, substantially all of the conduits 106 and 110 are so formed.

Referring particularly to FIG. 3, in the example shown portions 112, 114 of the supply conduit 106 establish axially longer segments and axially shorter segments, respectively. Likewise, portions 116, 118 of the return conduit establish axially longer segments and axially shorter segments, respectively. FIG. 3 shows that axially shorter segments 118 of the return conduit 100 are bordered by and spaced axially between transverse legs of respective axially longer segments 112 of the supply conduit 106. Similarly, axially shorter segments 114 of the supply conduit are bordered by and spaced axially between transverse legs of a respective axially longer segment 116 of the return conduit 110.

As discussed in one example below, when the conduits are inflated with working fluid, a proximal-most transverse segment 120 of the supply conduit ends at a first distally-extending axially-oriented segment 122, which merges at a distal end 124 with a second transverse segment 126, which in turn merges at an opposite end of the second transverse segment 126 with another distally-extending axially-oriented segment 128, and so on. Likewise, when the conduits are inflated with working fluid, a distal-most transverse segment 130 of the return conduit 110 ends at a first proximally-extending axially-oriented segment 132, which merges at a proximal end with a second transverse segment 134, which in turn merges at an opposite end of the second transverse segment with another proximally-extending axially-oriented segment 136, and so on.

In non-limiting examples and as shown in FIG. 3, in each conduit 106, 110, lengths of the axially-oriented segments sequentially alternate between a short length and a long length, while in contrast each transverse segment has substantially the same length as the other transverse segments. Additionally, a long axially-oriented segment of the supply conduit axially spans a short axially-oriented segment of the return conduit, and likewise a long axially-oriented segment of the return conduit axially spans a short axially-oriented segment of the supply conduit. Short axially-oriented segments of the conduits may be substantially straight and parallel to a long axis of the catheter as shown, while long axially-oriented segments (e.g., as shown 112 and 116) of the conduits can be concave.

While the particular INTRAVASCULAR HEAT EXCHANGE CATHETER WITH RIB CAGE-LIKE COOLANT PATH is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims. 

What is claimed is:
 1. A catheter, comprising: a heat exchange supply conduit configured to supply working fluid received from a source of working fluid to a distal location; a heat exchange return conduit communicating with the supply conduit at the distal location and configured to return working fluid to the source; wherein at least a portion of the supply conduit and at least a portion of the return conduit are configured in a serpentine configuration when working fluid flow therethrough; wherein serpentine portions of the supply conduit establish axially longer segments and axially shorter segments and wherein serpentine portions of the return conduit establish axially longer segments and axially shorter segments, and further wherein at least one axially shorter segment of the return conduit is bordered by and axially between transverse legs of an axially longer segment of the supply conduit and at least one axially shorter segment of the supply conduit is bordered by and axially between transverse legs of an axially longer segment of the return conduit.
 2. The catheter of claim 1, wherein at least when the conduits are inflated with working fluid, a proximal-most transverse segment of the supply conduit ends at a first distally-extending axially-oriented segment, which merges at a distal end with a second transverse segment, which in turn merges at an opposite end of the second transverse segment with another distally-extending axially-oriented segment.
 3. The catheter of claim 2, wherein at least when the conduits are inflated with working fluid, a distal-most transverse segment of the return conduit ends at a first proximally-extending axially-oriented segment, which merges at a proximal end with a second transverse segment, which in turn merges at an opposite end of the second transverse segment with another proximally-extending axially-oriented segment.
 4. The catheter of claim 3, wherein in each conduit, lengths of the axially-oriented segment sequentially alternate between a short length and a long length, while in contrast each transverse segment has substantially the same length as the other transverse segments.
 5. The catheter of claim 4, wherein a long axially-oriented segment of the supply conduit axially spans a short axially-oriented segment of the return conduit, and likewise a long axially-oriented segment of the return conduit axially spans a short axially-oriented segment of the supply conduit.
 6. A catheter, comprising: a heat exchange supply conduit configured to supply working fluid received from a source of working fluid to a distal location; a heat exchange return conduit communicating with the supply conduit at the distal location and configured to return working fluid to the source; wherein at least a portion of the supply conduit and/or at least a portion of the return conduit is configured in a serpentine configuration when working fluid flows therethrough.
 7. The catheter of claim 6, wherein at least a portion of the supply conduit is configured in a serpentine configuration when working fluid flow therethrough.
 8. The catheter of claim 6, wherein at least a portion of the return conduit is configured in a serpentine configuration when working fluid flow therethrough.
 9. The catheter of claim 6, wherein at least a portion of the supply conduit and at least a portion of the return conduit are configured in a serpentine configuration when working fluid flow therethrough.
 10. The catheter of claim 9, wherein serpentine portions of the supply conduit establish axially longer segments and axially shorter segments and wherein serpentine portions of the return conduit establish axially longer segments and axially shorter segments, and further wherein at least one axially shorter segment of the return conduit is bordered by and axially between transverse legs of an axially longer segment of the supply conduit and at least one axially shorter segment of the supply conduit is bordered by and axially between transverse legs of an axially longer segment of the return conduit.
 11. The catheter of claim 10, wherein at least when the conduits are inflated with working fluid, a proximal-most transverse segment of the supply conduit ends at a first distally-extending axially-oriented segment, which merges at a distal end with a second transverse segment, which in turn merges at an opposite end of the second transverse segment with another distally-extending axially-oriented segment.
 12. The catheter of claim 11, wherein at least when the conduits are inflated with working fluid, a distal-most transverse segment of the return conduit ends at a first proximally-extending axially-oriented segment, which merges at a proximal end with a second transverse segment, which in turn merges at an opposite end of the second transverse segment with another proximally-extending axially-oriented segment.
 13. The catheter of claim 12, wherein in each conduit, lengths of the axially-oriented segment sequentially alternate between a short length and a long length, while in contrast each transverse segment has substantially the same length as the other transverse segments.
 14. The catheter of claim 13, wherein a long axially-oriented segment of the supply conduit axially spans a short axially-oriented segment of the return conduit, and likewise a long axially-oriented segment of the return conduit axially spans a short axially-oriented segment of the supply conduit.
 15. The catheter of claim 14, wherein short axially-oriented segments of the conduits are substantially straight and parallel to a long axis of the catheter, while long axially-oriented segments the conduits are concave.
 16. An intravascular heat exchange catheter, comprising: serpentine-like supply and return conduits circulating working fluid with a heat exchange system to warm or cool a patient in which the catheter is intubated.
 17. The catheter of claim 16, wherein portions of the supply conduit establish axially longer segments and axially shorter segments and wherein portions of the return conduit establish axially longer segments and axially shorter segments, and further wherein at least one axially shorter segment of the return conduit is bordered by and axially between transverse legs of an axially longer segment of the supply conduit and at least one axially shorter segment of the supply conduit is bordered by and axially between transverse legs of an axially longer segment of the return conduit.
 18. The catheter of claim 17, wherein at least when the conduits are inflated with working fluid, a proximal-most transverse segment of the supply conduit ends at a first distally-extending axially-oriented segment, which merges at a distal end with a second transverse segment, which in turn merges at an opposite end of the second transverse segment with another distally-extending axially-oriented segment.
 19. The catheter of claim 18, wherein at least when the conduits are inflated with working fluid, a distal-most transverse segment of the return conduit ends at a first proximally-extending axially-oriented segment, which merges at a proximal end with a second transverse segment, which in turn merges at an opposite end of the second transverse segment with another proximally-extending axially-oriented segment.
 20. The catheter of claim 18, wherein in each conduit, lengths of the axially-oriented segment sequentially alternate between a short length and a long length, while in contrast each transverse segment has substantially the same length as the other transverse segments. 